A known example of a scanning observation apparatus is a scanning endoscope apparatus that scans a test site by irradiating the test site with illumination light. The illumination light is emitted from an optical fiber extending through a scope and passes through an illumination optical system. The scanning endoscope apparatus scans while displacing the emission end of the optical fiber with an actuator and deflecting the illumination light, detects light reflected at the test site, and displays an image (for example, see JP 5490331 B2 (PTL 1)).
This scanning endoscope apparatus acquires coordinate information of the scanning pattern of light of a predetermined color using a light irradiation coordinate detection module, such as a Position Sensitive Detector (PSD), provided with a coordinate information acquisition function. The scanning endoscope apparatus also stores information on optical characteristics that, using the light of the predetermined color as a reference, indicate the correspondence relationship between the image height and amount of aberration of light of another color. When using the coordinate information to detect that the light of the predetermined color has been irradiated on a position of the test site corresponding to a predetermined image height, the scanning endoscope apparatus detects the amount of aberration of the light of the other color at the predetermined image height using the information on optical characteristics. The scanning endoscope apparatus then acquires image correction information for correcting the chromatic aberration of magnification of the image generated in accordance with reflected light from the light of the other color, performs image correction processing on the basis of the image correction information, and displays an image of the test site.